species diversity and human activity

Question 1

what makes a natural ecosystem have a high biodiversity

Answer 1

lots of different species
high index of diversity

Question 2

what 3 things does farming impact in an ecoystem

Answer 2

• animals
• plants
• insects

Question 3

explain the ways farmers reduce biodiversity of plants (4 marks)

Answer 3

bigger fields
removal of hedgerows

farmers drain wetlands/ponds

removal of woodlands

overgrazing prevents the regeneration of woodland

monoculture (growing one crop)

less intercropping

increased use of organic fertilisers and pesticides/insecticides

Question 4

define intercropping

Answer 4

grow more than one type of crop in a field

Question 5

how do farmers reduce the biodiversity of animals

Answer 5

one type of livestock

Question 6

explain how a lower number of species reduces biodiversity

Answer 6

lower number of species
lower index of diversity
low biodiversity

Question 7

name the conservation and farming technique for these things:

1. hedgerows
2. ponds
3. grazing
4. pesticides
5. fertilisers
6. surface runoff
7. monoculture

Answer 7

1. farming: removal of hedgerows
   conservation: maintaining hedgerows
2. farming: filling in ponds and draining marshes
   conservation: maintain existing ponds and create new ones. leave wet areas
3. farming: overgrazing to prevent regeneration of woodland
   conservation: plant native trees on land with low species diversity
4. farming: use pesticides to kill pests
   conservation: decreased use of pesticides
   increased use of biological control
   increased use of GMO that are resistant to pests
5. farming: use of inorganic fertilisers
   conservation: crop rotation to include nitrogen fixing crop
   decreased use of fertilisers to increase fertility of soil
6. farming: escape of effluent into water
   conservation: plant trees and hedgerows to slow down flow of water
7. farming: monoculture and absence of crop rotation
   conservation: intercropping
   increased diversity = more predators = higher yield

grow wildflowers as these attract insects

Question 8

what are the 4 ways to investigate diversity

Answer 8

• observable characteristics
• base sequence of DNA
• base sequence of mRNA
• amino acid sequence

Question 9

state an advantage of investigating genetic diversity by observable characteristics

Answer 9

fast

Question 10

explain how observable characteristics allow you to investigate genetic diversity

Answer 10

there is variation within a species
this depends on the number and variety for alleles for a specific gene

Question 11

what are the limitations of investigating genetic diversity through observable characteristics

Answer 11

• many observable characteristics are coded for by more than 1 gene which makes it difficult to determine evolutionary relationships
• observable characteristics may be influenced by environment

Question 12

explain how the base sequence of DNA allows you to investigate genetic diversity

Answer 12

the more similar the base sequence between 2 species of DNA, the more closely related the different species are

the higher the % the more closely related that species is to the original species

Question 13

what is the % match based on when investigating the genetic diversity in the base sequence of mRNA and DNA

Answer 13

% match in base sequence of first 200 bases of a gene

Question 14

explain how the base sequence of mRNA allows you to investigate genetic diversity

Answer 14

more similar base sequence on the mRNA strand (copy gene) = the more closely related the species are

Question 15

why is the base sequence of mRNA used to investigate diversity

Answer 15

by comparing base sequence of mRNA you can measure diversity and determine evolutionary relationships

Question 16

how does analysing amino acid sequence allow you to investigate genetic diversity

Answer 16

the more similar the amino acid sequence of a protein = more closely related that the 2 species are

SO
the most closely related amino acids will have the most similar amino acid sequence

Question 17

how do immunological comparisons allow you to investigate genetic diversity

Answer 17

• albumin is a protein found in most species
• the antigens on albumin will produce an immune response
• species 2 : produce antibodies that are specific to antigen

SPECIES 2 ONLY PRODUCE ANTIBODIES

• antibodies from species 2 are injected into the blood of other species (e.g: A and B) that have albumin
• if the antigen on the albumin is close enough to species A it will bind to form a precipitate
• the greater the mass of the precipitate = the greater the similarity between antigens = more closely related species are to species 1

REMEBER GENE DETERMINES SHAPE OF ANTIGEN